Simulating Aeolus’s demise: a bird’s eye view

Aeolus’s mission is over, but weather forecasting is improved forever, and a new precedent has been set for safe satellite reentries. The trailblazing Earth Explorer returned through our atmosphere on 28 July, following the path it was guided on by ESA’s mission control over Earth’s most uninhabited regions, finally disintegrating over the Antarctic. 

A week-long series of manoeuvres led to this point. They had never been performed before and pushed the satellite to its limits. Aeolus was never designed to fly at such low altitudes – its thrusters and fuel reserves were not made to operate in the thick lower reaches of Earth’s atmosphere. 

Despite choppy skies and one evening where it seemed the attempt could fail, the successful reentry lowered the already small risk of surviving fragments landing where they shouldn’t. 

The chance of satellite debris falling on your head is three times less than a meteorite doing the same. Despite this, as our orbital highways get busier and reentries become more common, ESA went above and beyond to lower this even further. 

By turning Aeolus’s original fate – an uncontrolled, ‘natural’ reentry – into an assisted one, they reduced that risk another 42 times. 

This animation shows how the final moments for Aeolus could have gone, set to a sonification of Aeolus data, composed by Jamie Perera. 

Find out more about Aeolus’s final moments in the Rocket Science blog.

This simulation is created using a model of the Aeolus spacecraft, considering its shape, size, mass and materials, and the effect of 'aerothermodynamics' - the study of how high-velocity gases behave, including thermal effects between gases and solid surfaces.

The tool used, SCARAB, creates a simulation of Aeolus's reentry with ‘six degrees of freedom’, and shows the final moments of Aeolus's reentry, when the spacecraft is falling naturally in an uncontrolled descent.